package config

import (
	"errors"
	"fmt"
	"log/slog"
	"os"
	"strings"

	"github.com/spf13/cobra"
	"github.com/spf13/viper"

	"git.avsdev.uk/Go/job-search/internal/config"
)

func commandInit() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "init [config_path]",
		Args:  cobra.MatchAll(cobra.MinimumNArgs(0), cobra.MaximumNArgs(1)),
		Short: "Create a configuration file holding the defaults",
		Long: `Create a configuration file holding the defaults, at config_path or,
without one, the first config.yaml found in /etc/job-search then the working
directory (/etc/job-search/config.yaml if there is none). The test sources
(fts_mock and sleeper) are left out unless --all is given.`,
		PersistentPreRun: func(cmd *cobra.Command, args []string) {
			slog.Debug("command persistent pre-run", "command", "config.init")
		},
		PersistentPostRun: func(cmd *cobra.Command, args []string) {
			slog.Debug("command persistent post-run", "command", "config.init")
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			slog.Debug("command run", "command", "config.init")

			if err := cobra.MinimumNArgs(0)(cmd, args); err != nil {
				return err
			}
			if err := cobra.MaximumNArgs(1)(cmd, args); err != nil {
				return err
			}

			// Flags and arguments are valid from here on, so errors are runtime
			// failures: report them without cobra's usage text.
			cmd.SilenceUsage = true

			// With no path, the default locations are used.
			configFile := ""
			if len(args) > 0 {
				configFile = strings.TrimSpace(args[0])
			}
			if configFile != "" {
				// Use the config file given.
				viper.SetConfigFile(configFile)
			} else {
				// Search config in /etc or local directory.
				viper.AddConfigPath(config.EtcConfigPath)
				viper.AddConfigPath(".")
				viper.SetConfigName("config")
			}

			err := viper.ReadInConfig()
			if err == nil {
				return errors.New("configuration file already exists")
			}

			var notFound viper.ConfigFileNotFoundError
			if !errors.Is(err, os.ErrNotExist) && !errors.As(err, &notFound) {
				// Config file was found but another error was produced
				return err
			}

			path := viper.ConfigFileUsed()
			if path == "" {
				path = config.EtcConfigPath + "/config.yaml"
			}

			// A Viper of its own, holding only the keys to write: the global
			// one would write every default, the hidden sections' included.
			all, _ := cmd.Flags().GetBool("all")
			generated := viper.New()
			for key, value := range config.InitDefaults(all) {
				generated.Set(key, value)
			}
			generated.SetConfigFile(path)

			fmt.Print("writing default configuration to file: " + path + "\n")

			return generated.WriteConfig()
		},
	}
	cmd.Flags().Bool(
		"all", false, "also write the test sources (fts_mock and sleeper)",
	)

	// Config flag should be hidden as the config path should be provided
	cmd.SetHelpFunc(func(command *cobra.Command, args []string) {
		command.Flags().MarkHidden("config") //nolint:errcheck,gosec // a root flag, so it always exists
		command.Parent().HelpFunc()(command, args)
	})

	return cmd
}